by Michelle Healy, USA TODAY

by Michelle Healy, USA TODAY

A new review of studies looking how mid-level providers such as dental therapists impact oral health finds that they do increase the number of fillings and extractions performed in a population, but that they do not change the overall rate of dental decay or the rate of oral health disparities, says the report, released today.

The review focuses on 18 studies from five places where such mid-level practitioners provide care, Australia, Canada, Hong Kong, New Zealand, and tribal areas in Alaska. Seven of the studies were published before 1980, and some were published as early as the 1950s, says the report, in the Journal of the American Dental Association.

"Even the best studies available are of poor quality, and there is a clear need for additional research to assess the effectiveness of mid-level providers as a means of reduce overall disease burden," says the study. Minnesota is currently the only state where dental therapists are licensed to practice, in under-served communities and with a dentist's supervision.

The study concludes, however, that there is no difference in rates of dental decay in populations treated by therapists and those treated solely by dentists. It also concludes that no data are available to adequately address the cost-effectiveness of mid-level providers.

The American Dental Association opposes the use of mid-level practitioners. The organization of 157,000 dentists says it favors insurance reform, community water fluoridation, education and helping people overcome cultural, geographic and language barriers that keep them from dental care.